Plant biosafety levels

1. Ambreen Mehvish

2.  Exposure can occur during lab procedures of
Pathogen isolation
Culturing
 Inhalation of airborne spores can initiate mycoses
 Allergic reactions can also occur but not well
documented
 Plant pathogens are generally considered as Class I
 APHIS don’t address risk to humans..

4.  Anthroponoses
Diseases Transmissible between human
 Zoonoses
Humans to animals
 Sapronoses
Environmental sources to humans
 Phytoses
Plants to humans….

5.  Plant pathogens are not regarded as posing risks to
humans and needing safe practices for reducing worker
exposure:
Specimen examination
Culturing and diagnosis
Inoculation of plants
 USDA emphasis is on preventing introduction into the
environment..

6. BUT…..
THERE ARE CERTAIN PLANT PATHOGENS
WHICH CAN CAUSE DISEAESES IN
HUMANS… IF NOT HANDLED CAREFULLY IN
RESEARCH FACILITY

7.  Over 500 species isolated from humans
 5% are plant pathogens
28 bacterial species affect human

9.  About 300 species isolated from humans with
infectious diseases
 Atleast 50 are known as plant pathogens
 Most are Ascomycetes
 Mortality rate higher than bacteria
 Many associated with allergic asthma
 Most common Fusarium

12.  Plant viruses in cross kingdom taxa that replicate in
arthropod vectors (aphids)
 Topovirus, Phytoreovirus, Fijivirus, Oryzavirus etc
 Likely candidates for human diseases but not reported
 Other viruses have mosquitoes and ticks vector and
cause sever human hemorrhagic fever..

13.  Risk increasing activities
 Large scale cultures
 Aerosol Generating Procedures
 Use of needles & syringes
 Direct contact with skin wounds
 Risk reduction practices
 Gloves
 Minimize aerosal generation
 Filter respirators

14.  Higher risk individuals
 Immunocompromised adults
 Persons with allergic sensitivities

16.  Facilities- constructed and operated to achieve the
containment levels required for the pests concerned..
 The level required depends on the risk of the plant pest
escaping in the environment

17.  To provide a framework for ensuring appropriate
biological containment in facilities
 A containment classification system has been
developed..
 It has four containment levels:
1. Basic;
2. Plant Pest Containment Level 1 (PPC-1);
3. Plant Pest Containment Level 2 (PPC-2);
4. Plant Pest Containment Level 3 (PPC-3).

19.  The concept of biological containment is usually
applied to work done in
 Buildings,
Growth chambers or
Greenhouses
 which have, or present, physical barriers to prevent the
escape of pests.

20.  Basic containment is the lowest containment level for
plant pests
 It provides simple, but adequate, barriers to pest escape
 Basic containment is applicable for work with low to
very low risk plant pests for scientific, research,
educational, processing, industrial or exhibition
purposes.

21.  Establishing a field plot using plants infected with a
virus that can only be transmitted by grafting;
 using virus-infected plant tissue as a control in
an ELISA test; or
 using plant tissue infected with a common strain of
tobacco mosaic virus to inoculate tobacco plants for a
biology project.

22.  PPC-1 containment is the next highest containment
level for plant pests
 Facilities include permanent structures such as
laboratories, greenhouses and screenhouses.
 Windows that can be opened must be fitted
 An autoclave must be available to treat waste

23.  Inoculating host plants with isolates of plum pox or
other plant viruses in the absence of the vectors of
those viruses.

24.  PPC-2 facilities include permanent structures such as
laboratories and greenhouses but not screenhouses.
 Containment is achieved through facility design,
operational procedures and the use of specialized
equipment.

25.  use of primary containment devices;
 use of dedicated or disposable laboratory clothing;
 appropriate decontamination of solid and liquid
waste;
 pest monitoring and regular inspection of screens,
filters and caulking for defects;
 clear documentation of standard operating
procedures (SOPs)
 mandatory personnel training; and
 the availability of suitable emergency response plans.

26.  Restricted access via an anteroom;
 An on-site autoclave; and
 Greenhouses that are mechanically ventilated with
screened or filtered inlet and exhaust air.

27.  Sealing or screening all penetrations into the work area;
 Inward directional airflow and
 Access via a dedicated anteroom.

28.  Conducting plant inoculations with an isolate
of Ralstonia solanacearum Biovar 2, Race 3, the causal
agent of potato brown rot disease;
 Morphological examination and DNA extraction of
sporangia of Synchytrium endobioticum, the causal
agent of Potato Wart, and their use as diagnostic
controls;

29.  Growing chrysanthemum plants infected with Puccinia
horiana, the causal agent of chrysanthemum white rust;
 Conducting plant inoculations with specific races of the
corn pathogen Helminthosporium turcicu;
 Conducting fruit inoculations in a laboratory
using Alternaria gaisen, the causal agent of Black Spot
of pear;

30.  PPC-3 is the highest containment level for plant pests
 All PPC-1 and PPC-2 physical and operational
requirements apply to this containment level.

31.  designation of a person with responsibility for the
overall operation of the facility;
 a high level of physical security;
 restricted access with a log being kept of
personnel and visitors entering the facility;
 full clothing change before entering the facility
with the possibility of washing or showering on
exit, if required;

32.  checks to confirm inward directional airflow
and regular inspections for deterioration in
seals;
 a procedural manual, including standard
operating procedures (SOPs), that addresses all
emergencies including those relating to
containment.

33.  dedicated anterooms with change areas;
 sealed facilities with inward directional airflow from
"clean" to "dirty" areas;
 HEPA filtered exhaust air;
 drains routed to an effluent treatment system;
 electronic data transfer capability;
 emergency power for critical containment systems; and
 break-resistant glazing for greenhouses.

34.  conducting plant inoculations with isolates
of Phakopsora pachyrhizi, the causal agent of Asian
Soybean Rust, in an area in close proximity to
susceptible hosts;
 conducting plant inoculations with imported isolates
of Gymnosporangium yamadae, the causal agent of
Japanese Apple Rust, in an area in close proximity to
susceptible hosts;

35.  biocontrol research with exotic microbial plant pests
that are difficult to contain and in cases where the
establishment risks are poorly documented; or
 conducting plant inoculations with pests of
environmental and/or economic concern that have a
high establishment and/or trade potential risk and that
produce airborne spores, such as the
pathogen Phytophthora ramorum.

36.  Containment Standards for Facilities Handling Plant
Pests - First Edition (Canadian Food Inspection
agency)
 Biological safety, fifth edition by Robert P. Elis